Re: linux-next: build failure after merge of the tip tree (from the drm-intel tree)

[Peter Zijlstra]

On Tue, Jul 05, 2016 at 01:53:03PM +1000, Stephen Rothwell wrote:
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index d3502c0603e5..1f91f187b2a8 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -3290,7 +3290,7 @@ i915_gem_retire_work_handler(struct work_struct *work)
>  	 * We do not need to do this test under locking as in the worst-case
>  	 * we queue the retire worker once too often.
>  	 */
> -	if (lockless_dereference(dev_priv->gt.awake))
> +	if (/*lockless_dereference*/(dev_priv->gt.awake))
>  		queue_delayed_work(dev_priv->wq,
>  				   &dev_priv->gt.retire_work,
>  				   round_jiffies_up_relative(HZ));
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index f6de8dd567a2..2c1926418691 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3095,7 +3095,7 @@ static void i915_hangcheck_elapsed(struct work_struct *work)
>  	if (!i915.enable_hangcheck)
>  		return;
>  
> -	if (!lockless_dereference(dev_priv->gt.awake))
> +	if (!/*lockless_dereference*/(dev_priv->gt.awake))
>  		return;
>  
>  	/* As enabling the GPU requires fairly extensive mmio access,

Right, neither case appears to include a data dependency and thus
lockless_dereference() seems misguided.